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Title: High Power Operation of the JLab IR FEL Driver Accelerator

Abstract

Operation of the JLab IR Upgrade FEL at CW powers in excess of 10 kW requires sustained production of high electron beam powers by the driver ERL. This in turn demands attention to numerous issues and effects, including: cathode lifetime; control of beamline and RF system vacuum during high current operation; longitudinal space charge; longitudinal and transverse matching of irregular/large volume phase space distributions; halo management; management of remnant dispersive effects; resistive wall, wake-field, and RF heating of beam vacuum chambers; the beam break up instability; the impact of coherent synchrotron radiation (both on beam quality and the performance of laser optics); magnetic component stability and reproducibility; and RF stability and reproducibility. We discuss our experience with these issues and describe the modus vivendi that has evolved during prolonged high current, high power beam and laser operation.

Authors:
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Publication Date:
Research Org.:
Thomas Jefferson National Accelerator Facility, Newport News, VA
Sponsoring Org.:
USDOE Office of Science (SC)
OSTI Identifier:
921661
Report Number(s):
JLAB-ACT-07-697; DOE/OR/23177-0270
TRN: US0801671
DOE Contract Number:
AC05-06OR23177
Resource Type:
Conference
Resource Relation:
Conference: 2007 IEEE Particle Accelerator Conference, Albuquerque, NM, 25-30 June 2007
Country of Publication:
United States
Language:
English
Subject:
43 PARTICLE ACCELERATORS; ACCELERATORS; CATHODES; ELECTRON BEAMS; HEATING; INSTABILITY; LASERS; LIFETIME; MANAGEMENT; OPTICS; PHASE SPACE; PRODUCTION; RF SYSTEMS; SPACE CHARGE; STABILITY; SYNCHROTRON RADIATION

Citation Formats

Kevin Beard, Stephen Benson, George Biallas, James Boyce, Donald Bullard, James Coleman, David Douglas, H. Dylla, Richard Evans, Pavel Evtushenko, Christopher Gould, Albert Grippo, Joseph Gubeli, David Hardy, Carlos Hernandez-Garcia, J. Hovater, Kevin Jordan, John Klopf, Rui Li, Steven Moore, George Neil, Benard Poelker, Thomas Powers, Joseph Preble, Robert Rimmer, Daniel Sexton, Michelle D. Shinn, Christopher Tennant, Richard Walker, Gwyn Williams, and Shukui Zhang. High Power Operation of the JLab IR FEL Driver Accelerator. United States: N. p., 2007. Web.
Kevin Beard, Stephen Benson, George Biallas, James Boyce, Donald Bullard, James Coleman, David Douglas, H. Dylla, Richard Evans, Pavel Evtushenko, Christopher Gould, Albert Grippo, Joseph Gubeli, David Hardy, Carlos Hernandez-Garcia, J. Hovater, Kevin Jordan, John Klopf, Rui Li, Steven Moore, George Neil, Benard Poelker, Thomas Powers, Joseph Preble, Robert Rimmer, Daniel Sexton, Michelle D. Shinn, Christopher Tennant, Richard Walker, Gwyn Williams, & Shukui Zhang. High Power Operation of the JLab IR FEL Driver Accelerator. United States.
Kevin Beard, Stephen Benson, George Biallas, James Boyce, Donald Bullard, James Coleman, David Douglas, H. Dylla, Richard Evans, Pavel Evtushenko, Christopher Gould, Albert Grippo, Joseph Gubeli, David Hardy, Carlos Hernandez-Garcia, J. Hovater, Kevin Jordan, John Klopf, Rui Li, Steven Moore, George Neil, Benard Poelker, Thomas Powers, Joseph Preble, Robert Rimmer, Daniel Sexton, Michelle D. Shinn, Christopher Tennant, Richard Walker, Gwyn Williams, and Shukui Zhang. 2007. "High Power Operation of the JLab IR FEL Driver Accelerator". United States. doi:. https://www.osti.gov/servlets/purl/921661.
@article{osti_921661,
title = {High Power Operation of the JLab IR FEL Driver Accelerator},
author = {Kevin Beard and Stephen Benson and George Biallas and James Boyce and Donald Bullard and James Coleman and David Douglas and H. Dylla and Richard Evans and Pavel Evtushenko and Christopher Gould and Albert Grippo and Joseph Gubeli and David Hardy and Carlos Hernandez-Garcia and J. Hovater and Kevin Jordan and John Klopf and Rui Li and Steven Moore and George Neil and Benard Poelker and Thomas Powers and Joseph Preble and Robert Rimmer and Daniel Sexton and Michelle D. Shinn and Christopher Tennant and Richard Walker and Gwyn Williams and Shukui Zhang},
abstractNote = {Operation of the JLab IR Upgrade FEL at CW powers in excess of 10 kW requires sustained production of high electron beam powers by the driver ERL. This in turn demands attention to numerous issues and effects, including: cathode lifetime; control of beamline and RF system vacuum during high current operation; longitudinal space charge; longitudinal and transverse matching of irregular/large volume phase space distributions; halo management; management of remnant dispersive effects; resistive wall, wake-field, and RF heating of beam vacuum chambers; the beam break up instability; the impact of coherent synchrotron radiation (both on beam quality and the performance of laser optics); magnetic component stability and reproducibility; and RF stability and reproducibility. We discuss our experience with these issues and describe the modus vivendi that has evolved during prolonged high current, high power beam and laser operation.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = 2007,
month = 8
}

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  • Jefferson Lab is building a free-electron laser (FEL) to produce continuous-wave (cw), kW-level light at 3-6 {mu}m wavelength. A superconducting linac will drive the laser, generating a 5 mA average current, 42 MeV energy electron beam. A transport lattice will recirculate the beam back to the linac for deceleration and conversion of about 75% of its power into rf power. Bunch charge will range up to 135 pC, and bunch lengths will range down to 1 ps in parts of the transport lattice. Accordingly, space charge in the injector and coherent synchrotron radiation in magnetic bends come into play. Themore » machine will thus enable studying these phenomena as a precursor to designing compact accelerators of high-brightness beams. The FEL is scheduled to be installed in its own facility by 1 October 1997. Given the short schedule, the machine design is conservative, based on modifications of the CEBAF cryomodule and MIT-Bates transport lattice. This paper surveys the machine design.« less
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  • Abstract not provided.